Case T-558/23: Judgment of the General Court of 8 October 2025 – Swissgrid v ACER (Energy – Internal market for electricity – Guideline on electricity balancing – Article 1(6) and (7) of Regulation (EU) 2017/2195 – European platform for the exchange of balancing energy from frequency restoration reserves with automatic activation – Non-participation of the Swiss Transmission System Operator – Appeal brought before the ACER Board of Appeal – Specific conditions and arrangements for appeals – Article 28 of Regulation (EU) 2019/942 – Inadmissibility for lack of standing to bring proceedings before the Board of Appeal – Lack of direct concern – Plea of illegality)